Information
A locally logged-on user who presses Ctrl-Alt-Delete, when at the console, can reboot the system. If accidentally pressed, as could happen in the case of a mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot. In the GNOME graphical environment, risk of unintentional reboot from the Ctrl-Alt-Delete sequence is reduced because the user will be prompted before any action is taken.
Solution
Configure the system to disable the Ctrl-Alt_Delete sequence for the command line with the following command:
# systemctl mask ctrl-alt-del.target
If GNOME is active on the system, create a database to contain the system-wide setting (if it does not already exist) with the following command:
# touch /etc/dconf/db/local.d/00-disable-CAD
Add the setting to disable the Ctrl-Alt_Delete sequence for GNOME:
[org/gnome/settings-daemon/plugins/media-keys]
logout=''